Year	Percent
1973-01-01	41.501900000000000
1974-01-01	50.345900000000000
1975-01-01	57.843400000000000
1976-01-01	61.665700000000000
1977-01-01	61.867300000000000
1978-01-01	54.928700000000000
1979-01-01	52.628400000000000
1980-01-01	49.969300000000000
1981-01-01	51.694700000000000
1982-01-01	51.805900000000000
1983-01-01	51.699000000000000
1984-01-01	50.775400000000000
1985-01-01	49.464900000000000
1986-01-01	49.361999999999995
1987-01-01	49.949900000000000
1988-01-01	51.054200000000000
1989-01-01	44.966900000000000
1990-01-01	41.854400000000000
1991-01-01	43.111600000000000
1992-01-01	46.900200000000000
1993-01-01	52.320000000000000
1994-01-01	58.682300000000000
1995-01-01	66.169300000000000
1996-01-01	62.148999999999994
1997-01-01	64.533100000000000
1998-01-01	71.109500000000000
1999-01-01	81.283700000000000
2000-01-01	89.222700000000000
2001-01-01	93.102200000000000
2002-01-01	86.910900000000000
2003-01-01	77.105200000000000
2004-01-01	72.773200000000000
2005-01-01	74.137700000000000
2006-01-01	75.599700000000000
2007-01-01	75.735900000000000
2008-01-01	77.550900000000000
2009-01-01	76.633000000000000
2010-01-01	76.404500000000000
2011-01-01	74.733700000000000
2012-01-01	75.155200000000000
2013-01-01	68.893999999999990
2014-01-01	71.156900000000000
2015-01-01	81.556900000000000
2016-01-01	84.495200000000000